Transport, availability and ecotoxicology of nanoparticles in the environment: interactions with natural organic matter in aquatic systems

• Grant number: 16/10675-3
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: November 01, 2016
• End date: October 31, 2017
• Field of knowledge: Physical Sciences and Mathematics - Chemistry
• Principal Investigator: André Henrique Rosa
• Grantee: Cláudia Hitomi Watanabe
• Supervisor: Fabien Marc Benedetti
• Host Institution: Instituto de Ciência e Tecnologia. Universidade Estadual Paulista (UNESP). Campus de Sorocaba. Sorocaba , SP, Brazil
• Institution abroad: Université Paris Diderot - Paris 7, France
• Associated to the scholarship: 14/20979-4 - Transport, availability and ecotoxicology of nanoparticles in the environment: interactions with natural organic matter in aquatic systems, BP.DR

Abstract

When introduced in environment, manufactured nanoparticles (NPs) can interact with biotic and abiotic molecules yielding a transformed NP usually coated with these molecules (natural coating). These different forms of the NPs should be considered as new materials because they will have distinct properties from the as released NPs forms. In fact, these in situ transformations of the NPs have relevant impacts on their toxicological effects, having new or additional risks still not studied. This project aims to determine, understand and predict the impact of natural molecules in the transformations and bio-effects of Ag NPs, widely used as antibacterial agents. Despite the growing interest and use of these NPs, the gathered knowledge on their environmental consequences is still scarce, since the large majority of the studies do not consider the effect of the presence of natural coatings around the particles. In fact, most of the studied do not even determine the effects of the presence of manufactured coatings. Generally, NPs manufacturers add ionic or polymeric coatings to improve their mobility and stabilization in terms of size. Although the possible effects of these manufactured coatings in the NPs behavior there is not systematically studied about their impact. This project aims to overcome the current uncertainty about the environmental safety of manufactured coated NPs, and explore the impact of natural molecules on their environmental risk. The project objectives are: i) characterize the manufactured coated Ag NPs in absence and presence of natural molecules including Humic Substances (HS) and Extracellular Polymeric Substances (EPS), ii) determinate the biocompatible and bioadverse effects of the transformed NPs on the algae Pseudokirchneriella subcapitata and the microcrustacean Ceriodaphnia dubia, iii) identify the key signatures of the manufactured and natural coatings that affect the fate and biocompatibility of the NPs, and iv) evaluate the transfer of the transformed NPs in the food chain alga-microcrustacean. Thus, this project purposes to introduce a standardized and improved evaluation of the ecotoxicology in order to increase the competitiveness and safety of nanostructured products. (AU)